Safety device for gas mains and holders.



G. BAEHR. SAFETY DEVICE EOE GAS MAINS AND HOLDERS.

APPLIUATION FILED 0CT.20, 1909.

Patented Jan. EE0; 1912.

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INVENTOR WITNEssl-:s

G. BAEHR.

- SAFETY DEVICE EOE GAS MAINS AND HGLDERS.

APPLIUATION FILED 0011.20, 1909.

Patented 11113111912.

2 SHEETS-SHEET 2.

A@ ha STATES GEORGE BAEHR, OF AMPERE, NEW JERSEY, ASSIGNOR TO NATIONAL` TUBE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF JERSEY.

SAFETY DEVICE FOR G-AS MAINS AND HOLDERS.

Specification of Letters Patent.

Patented Jan. 30, 1912.

Application led October 20, 1909. Serial No. 523,709.

To all 'whom t may concern.' Be it known that I, GEORGE BAEHR, of

`Ampere, county of Essex, and State of New Jersey, have invented a new and useful Safety Device for Gas Mains and Holders Figure 1 is a partly diagrammatic side elevation showing a gas main leading from a gasometer or gas-holder, or other1 source of supply to the engine cylinders-ofv a gas engine plant or a powerrstation having generators driven by gas engines. Fig. 2 is 'a detailed sectional elevation on a largerscale of the gas main showing the fire door, and its operating mechanism forming part of my invention. Fig. 3 is a transverse section of the same on the line III- III of Fig. 2. Fig. 4 is a detail sectional eleva-tion showing the means employed in sealing the fire door when seated in its closed position. My inventionrelates to the handling and controlling of manufactured or combustible gases, the gas engines employing such gases as fuel and the mechanismoperated by such gas engines and it more particularly relates to the handling of blast furnace gases in cleaning, storing and conducting such gases to the place of use and to the controlling of apparatus usingl such gases in generating power. In the handling of such gases, are conducted from the blast furnace, gas producer, or other source of supply in suitable gas mains to a gas washing or scrubbing plant where they are freed from impurities and cleaned vso as to be adapted for the use for which they are intended. The cleaned gases are then conducted to the gas engines or other point of use where they are used in producing power. A gasometer or gas holder is usually installed ata suitable point in the length of the gas-main between the source of supply and the place of use to store up the gases as madev and deliver them as required, although in some cases the gasholder is dispensed with, the gas mains acting as the place of storage. y

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' In operating gas engines, particularly the large units used in driving electric generators with blast furnace gases as fuel, the gases have frequently become ignited by a back fire from such gas engine cylinders. When such back tiring occurs and enough air has been admitted into the' gas mains to form an explosive mixture, explosions have occurred causing great damage to the gasmain; gas holder, gas engines and surround# ing property.

The object of my invention is to provide improved means by which such explosions are rendered impossible and the liability of damage to the apparatus used in connection with such gases is overcome and prevented.

Fig. l) to the gas engines'from a gasometer,

or gas-holder, or, when the gas holder is not employed, How direct from the blast furnaces,- gas producer, or other source of supply.

A rotary gas washer forming part of the gas washing plant is usually employed in cleaning the 4gases and is preferably located between the source of gas supply and the gas engines. Such rotary washers, which are practically pressurel blowers, as they are adapted to increase the pressure of the gases on the discharge side above that on the inlet side of the washer are generally driven by an electric motor, which is indicated in the drawings by thenumeral 3.

At a suitable location `on the gas-1nain,V

preferably near the point where the gases are conducted through branch pipes leading from the gas-main 2 to the cylinders of the gas engines is a pivoted lire door 4 (shown dotted in its open position in Fig. l of the drawings). The door 4 is keyed or other- 65 Another object of the invention is to provide improved means for controlling the opcomplete wise secured to the shaft 5 so as to, rotate or y oscillate with the shaft, which is mounted in suitable bearings on the gas main. The shaft 5 is provided, on its end extending to the outside of the gas main, with abellcrank having one arm 6 which is provided with a counter-weight 6a and a second arm 7. The end of the arm 7 is held in the position shown in the drawings by the pivoted trigger or latch 8, which'is secured by a pin or shaft 9 to the bracket 1() on the side of the gas main 2. The latch 8 is adapted to hold the counterweighted bell crank and maintain the lire door 4 in its open position so as to permit the gases to iow through the gas main beyond the lire-door toward the gas engine cylinders or other place of use. The latch 8 is connected at one end to the solenoid core. 11, the coil 12 of which is mounted on the bracket 10 on the side of the gas main. Also mounted on the gas main 2 and preferably at some distance from the tire door 4 (in one instance this distance being about 600 ft.) is a branch opening or hat pipe 13, which is closed by a flexible diaphragm 14. This diaphragm is adapted to be actuated by changes in the pressure of gases in the main and is arranged to hold the bridge piece 15 on the upper end ot its stem 14a in engagement with the terminals 16a, so as to and maintain a circuit through the wires 17, 17 a which lead from the main wires 18, 18a and supply current to energize the solenoid coil 12 upon the bracket 10.

The main feed wires 18, 18@L supply current through wires 19, 19a to the motor 3 which drives the rotary gas washer and connected in the circuit formed by these wires is a magnetic switch having a stationary contact 20 and movable contact 21. The movable contact 21 is arranged to be held in engagement with the contact 20 by the solenoid core 22 when the coil 23 forming part of this switch is energized.

The coil 23 is energized by current supplied through a shunt circuit formed by the wires 23a, 23a leading from the wires 19, 19a and resistance 24 is introduced in the circuit formed by these wires to prevent overheating of the coil 23, thiscoil being energized during the time the motor 3 is in operation.

' The lower end of the solenoid core 22 is connected to a bell crank or lever 25 having a bridge piece 26 on its lower end whiclris arranged to engage with terminals 24a'and cut out the resistance 24 when the core 22 is being moved into position in bringing the contacts 2() and 21 of the magnet-ie switch into engagement after such engagement has .been broken to stop the operation of the motor. A switch 27 is provided to cutout the solenoid 23 and the motor 3 from the feed wires 18, 18a when desired.

The circuit through the solenoid core 23 is completed by means of a bridge piece 28 on the lower end of the core 29 for the solenoid coil 30. The bridge piece 28 engaging with terminals provided on the wires form a shunt circuit from the motor circuit to the coil 23. The coil 30 is connected by wires 30 and 31 with a battery 32 through the solenoid coil 33 and the-bridge piece 34 on the upper end of the core 11 for the solenoid coil 12.

The ignition circuit for the gas engines formed by the wires 35 and 35a is completed by a bridge piece 36 on the end ofthe core 37 of the solenoid having the coil 33 and the circuit breakers 39, through which the current generated in driving the gas engine is transmitted to the bus `bars are provided with solenoid coils 38 connected in parallel to the ignition circuit formed by the wires 35-35 of the power station. The coils 38 are provided with resistance 40 to prevent heating and vthe cores 41on the solenoids formed by the coils 38 are provided on their upper ends with bridge pieces 42 by which the resistance 40 is cut out in actuating the solenoid core 30 after the circuit breakers have been tripped to cut out the generators with which they are connected to the bus bars.

A suitable ammeter 42 is provided in the circuit formed by the wires 31, 31a to show variations in the current supplied for actuating the solenoids connected with this circuit and to indicate variations from the normal current.

The gas main 2 is provided with eXplosion doors 43, cleaning doors, etc., at suitable points in its length and a cleaning door having a bell 44 is provided on the gas main below the fire door 4 to facilitate cleaning of the gas main at this point.

' The seat 45 for the lire door 4 is provided with one or more annular grooves 46 in which asbestos or similar lnaterial is packed to form a gasket or seat for the door when in its closed position. The inner surface of the door 4 is provided with annular projections 47 which are adapted to register with the grooves 46 and be jammed into the asbestos in those grooves when the door is moved into its closed position and in this way maintain a tight joint to prevent passage of the gases past the door when the door is closed.

In the operation of my improved apparatus, when back tiring occurs in the gas engine cylinders and there should be suiicient air mixed with the gases in the main to form a combustible or explosive mixture, the gases will be ignited and an internal explosion take place in the gas main 2. lhen this occurs, the pressure in the gas main is instantly increased and the diaphragm'14 will be actuated to break contact between the bridge piece 15 and the termr nals on thewir'es 17, 17a and break the circuit leading to the solenoid coil 12. The

increasedA pressure in the gas main Will act Vthe explosion doors on the on the diaphragm 14 before reaching the lire door 4. When the circuit is broken to the solenoid coil l1, its core 12 drops and,

through the latch 8 secured to its lovyer end releases the arm 7 of the bell crank on the pivoted shaft 5. Theicounterweight 6a then swings the re door 4 into its closed position before the effect of the explosion has reached this point in the gas main. When the door is closed, the effect of the explosion in the gas main passing this point is prevented and liability of the ignition of the large quantity of gas usually behind the. lire door is overcome. The increase in pressure in the mains is relieved by opening of as main. lVhen the core l2 is dropped by deenergizing the coil 11, the bridge piece 34 on its upper end is moved to break the circuit through' the Wires 3l, 31ZL so as to denergize the coil 30 and the coil 33. When these coils become denergized the core 29 is dropped to break the circuit lead-A ing to the motor 3 and the core -38 is dropped so as to breakthe ignition circuit formed by the lWires 35 and 35a which lead to the gas engine cylinders; The breaking of the circuit through the Wires 35, 35@L also denergize t-he coils 38 on the circuit breakers 39 andby the dropping of their cores 4l trip the circuit breakers and cut out the gasengine driven generators from'the bus bars. When the circuit leading to the motor 3 is broken'the core 20 connected into this circuit is denergized and its core 22 drops so as to actuatev the magnetic switch and break connect-ion between the contacts 20 and 2l until such time as the coil 2O is again energized. After the eli'ects of such Van explosion have disappeared, the explosion doors 43 on the gas main are closed` and the lire door is lifted (by hand) so as to be again held in its open position by the latch or'trigger 8. The diaphragm moves back into position to again complete the circuit through the bridge piece 15 and Wires 17, 17a when the pressure of gases'in the main is reduced to normal and-the completion of this circuit again energizes the coil l2 and causes lit to lift its core 11 and bringthe bridge piece 34 on the upper end of this core-in position to complete the Vvcircuit through the wires 3l, 31a. lVhen this circuit is completed, the coil 33 and the coil 30 are again energized and caused to move their cores into position to complete, through the bridge piece 36the ignition circuit leading to the engines and through the bridge piece '28 the shunt circuit leading to the-electric motor 3.4 lVhen the shunt circuit leading t o the motor 3 is completed by raising the core 29 andbridge piece 28, the coil. 20 becomes again energized .and

.lifts its core 22 so as to move the-movablel contact 21 of the magnetic switch engagement With the stationary .Contact 20 and again supply current to lthe motor 3, causT ing' the gas Washer or Washers to again begin operations.

The advantages of my invention will be apparent to those skilledin the art. Thev apparatus is simple and is easily kept in repair. Byits use the possibility of explosions caused by back firing Jfrom the gas; engine ,cylinders reachingto the gasometers or gas holder or beyond the fire door in the gas lmain is prevented and liabilityof damage to the apparatus is overcome. The occurrence of such explosions cause the generators driven bythe gas engines to be ins'tantly, cut out from the bus bars and in this Way damage to the generators is prevented. Such explosions also cause the ignition circuit to the gas engines to be'broken and the engines to4 be stopped until the again restored to their gases have been normal pressure.

Modifications in the-construction and arrangement of the parts may be made Without departing from my invention.

' Icla'inu:`

1.`In apparatus of the character described, a gas main forA conducting gases to a gas engine,- 'a circuit breaker adapted to operatively complete thefcircuit leading from a generator connected to said gas engine, a tire door-on the gas main arranged to close and prevent ioW of gases therethrough, means actuated by a change in pressure in the'gas'main for Closing vsaid door and means adapted to tripsaid circuit breaker When the lire door is beingclosed.

2. In.' apparatus of the character v4described, a gas main for conducting gases to a gas engine, a circuit breakeradapted to operate to break the ignition circuit leading to said gas engine, a fire door on Athe gas maln arranged to close and prevent' flow of gases therethrough, means actuated by a change i'n pressure in the gas main for closing said door and means adapted to actuate said circuit breaker to break the ignition circuit to the door is being closed.

3. In apparatus ofthe character described, a gas main for conducting gases to a gas engine, a circuit breaker adapted to break the ignition circuit leading to said engine, a tire door on the gas main adapted' to close a'nd prevent passage ofgases therethrough, means actuated by a change in ,pressure in the said gas main for closing said door, means arranged to break the ignition circuit of the gas engine connected to said gas main and means adapted to stop the rotary Washerl When .said fire door is,

-being closed.

4. In apparatus of the character described, a gas main for conducting gasesto gas engine when the re 'I a gas engine having a rotary gas Washer n testimony whereof, l have hereilrrto"v therein, a fire door on the. gas main arranged set my hand. to close and prevent passage of gases therethrough, means operated by a change in GEO BAEHR' 5 pressure in the gas main for closing said Witnesses:

door, and means arranged`t0 stop the gas JOHN FOX,

washer when said fire door is being closed. CHAs, J. BOYD. 

